Electronic excitations of theYBa2Cu3O7−xsuperconductor: A study by transmission electron-energy-loss spectroscopy with an electron microprobe

Abstract

Interband and core-level transitions and plasmon resonance in the high-temperature oxide superconductor $\mathrm{Y}{\mathrm{Ba}}_2{\mathrm{Cu}}_3{\mathrm{O}}_{7-x}$ were studied by transmission electron-energy-loss spectroscopy using an electron microprobe ∼5-10 Å in size. Both single-crystal and polycrystalline ceramic samples have been examined. No significant change in electronic structure was observed at the grain boundaries. A 13.5-eV interband-transition peak was found to be sensitive to damages created by ion-beam bombardment.